The Universe Made Simple/The Solar System

Everyone learns about our solar system in elementary school, but what is the solar system?

The eight planets and the sun make up the Solar System. It also includes moon, comets, asteroids, minor planets, dust, and gas. In addition, some of these things are labeled like the asteroid belt, Kuiper belt, and the Oort cloud.

Our solar system is 4.5 billion years old. In general, objects orbiting a star constitute a solar system. The prevailing theory, called "nebular hypothesis" seems to indicate that solar systems evolve from giant clouds of dust and gas. That this cloud coalesces due to gravity's effect, which forces the cloud to collapse under its own weight. This causes the entire cloud to start circling as if it was running down a drain in the middle where a start is formed. The dust continue to aggregate until small clumps of the dust began to form. These clumps became the planets and moons and asteroids are not only leftover material but the result of collisions that ultimately result in stable orbits.